1. Field of the Invention
The present invention relates to an electronic still camera which permits purely electronic photographing of an object and, more particularly, to improvement in a recording unit of such an electronic camera.
2. Description of the Prior Art
Recently an electronic still camera has been proposed which employs, in combination, an optoelectro transducer, such as a solid state image sensor or pickup tube, and a recording unit using an inexpensive and large-capacity magnetic tape as a recording medium. Such a camera is adapted to take a still picture of an object purely electronically and to record the picture on the magnetic tape so that the image may be reproduced through the use of a separately provided television system or printer. This type of camera is attracting attention as a future substitute for the existing optical camera which involves chemical treatment of the film for development. The electronic still camera, though promising as mentioned above, must be still improved for miniaturization, lower manufacturing cost and less power dissipation before put to practical use. The optoelectro transducer, a control circuit and other electronic circuits can sufficiently be miniaturized and recuded in cost and in power consumption through utilization of recent marked developments in semiconductor integrated circuit technologies. Accordingly, in order to bring a practical electronic still camera to realization, it is necessary that the magnetic tape recording unit including a motor and other electrical devices be adapted for miniaturization, lower cost and lower power consumption.
On the other hand, since still photography is intended primarily for independently observing images of individual frames, it is not suitable, for the reproduction of still images, to employ a motion picture image reproducing method according to which a plurality of closely related recorded images are reproduced in the same sequence as that for recording; namely, there is great need to quickly reproduce an optimum one of a number of frames or a plurality of frames obtained by mutli-exposure photographing one after another. However, a magnetic tape is essentially a sequential file, and hence is difficult to randomly access. Therefore, it is necessary to take some measures to improve its random accessibility for reproducing. It has been regarded as difficult to achieve high random accessibility while fulfilling the requirements for miniaturization, low cost and small power dissipation of the magnetic tape recording device, and no satisfactory electronic still camera has been proposed yet.